IPv6 addresses are 128 bit long and provide an address space of 2^128 addresses.

IPv6 addresses are separated into eight blocks of four hexadecimal digits each. Blocks are separated by colons. Leading zeros can be shortened.

IPv6 addresses also use network prefixes, which are specified in slash notation. The prefix is used to specify routes or address ranges, not a network ID. Routing table entry for IPv6

IPv6 addresses are automatically assigned by neighboring routers or DHCPv6 servers. Also, computers assign themselves a connection local address that is used only around local subnet

 


  • All local unicast addresses begin with fe80, i.e. the first 10 bits represent the format prefix, then 54 bits with zeros and then the interface ID.
  • cope of validity is the local connection
  • necessary for neighbour determination, always automatically configured

Structure of IPv6 addresses compared to IPv4 addresses


IPv6

IPv4

Example

2001:0db8:85a3:08d3:1319:8a2e:0370:7344

183.252.182.113

used Character

0-9, a-f

0-9

basic structure

8 16bit groups with 4 digits each, separated by ":"

4 octets (8bit) with 3 digits each, separated by "."

Number of possible addresses

approx. 340,28 sextile ions

approx. 4.29 billion

Comparison of typical IPv4 and IPv6 addresses

Address type

IPv6

IPv4

Special addresses:

unspezifizierte Adresse

0:0:0:0:0:0:0:0 bzw.
           ::           /128

0.0.0.0

localhost, loopback

0:0:0:0:0:0:0:0 bzw.
           ::1         /128

127.0.0.1

link-local unicast = APIPA

fe80::  …… /10

169.254.0.0 /16

global Unicast (öffentl.)

2001: …… (for providers)

145.23.74.120

site-local Unicast, private

Unique Local Adresses

fec0: …… -> replacements

fc00: …… /7

10.0.0.0 /8

172.16.0.0 /12

192.168.0.0 /16